1) Field of the Invention
This invention relates generally to material handling equipment. More particularly, the present invention relates to a hand truck which allows for loading and unloading of objects thereon such as cases of beverage cans, in a manner which substantially eliminates any necessity for the operator to bend over in order to place an object onto the hand truck or to remove an object therefrom.
2) Related Prior Art
Hand trucks for transporting objects have been in use for many years. Such hand trucks are generally comprised of a nose which is fixed in an essentially perpendicular orientation to a support frame, with a set of wheels located at the lower end of the frame close to the nose. The nose is loaded with objects, either by placing objects directly thereon or by sliding the nose underneath the object. The support frame is then grasped by the operator and the wheels are temporarily immobilized while the operator rotates the support frame to lift the nose, and the objects placed thereon, until only the wheels remain on the ground. The hand truck can then be rolled by the operator to transport the objects thereon to a desired location. When it is desired to unload the hand truck the wheels are again immobilized and the nose is lowered until it rests on the ground. The operator may then remove objects directly from the hand truck, or the hand truck may be moved by sliding the nose from beneath the objects.
It has often been desirable for certain types of lifting requirements to modify the standard hand truck to make it more useful to the operator during loading and unloading thereof. Such modifications usually include a nose which is movable along the support frame in such a manner that the nose may be adjusted to a convenient position for either loading or unloading of objects thereon. A hand truck exemplary of this design is shown in U.S. Pat. No. 3,052,323 to Hopfeld which shows a hand truck having a movable nose which is adjustable along the frame by means of a chain and hydraulic pump. Other hand trucks exemplary of this concept are U.S. Pat. No. 3,907,138 Rhodes, U.S. Pat. No. 3,704,799 Morris, Jr. and U.S. Pat. No. 2,598,489 Bayer et al., which show hand trucks which have been modified to allow the nose to adjust along the frame thereof by means of a threaded screw.
In each of the prior art devices, the nose must be positioned by the operator through the operators actuation of the mechanism which moves the nose. This can become very inconvenient when the operator must load and unload a very large number of objects. Since the operator must readjust the location of the nose each time an object is loaded or unloaded from the hand truck, a very large amount of time can be expended in operating a hand truck when a very large number of objects must be loaded and unloaded. An example of this inconvenience can be illustrated in the situation where a delivery person delivering objects such as cases of beverage cans, must quickly load a hand truck with several cases of beverage cans and move them a very short distance into a store and then quickly unload them again. In this instance, a requirement for the operator to readjust the nose location in between loading and/or unloading of each individual case of beverage cans, can easily triple or quadruple the time factor involved in moving the cases of beverage cans into the store.
It is also known in the hand truck art to include an auxiliary set of wheels associated with a swing frame that is pivotally attached to the side of the main frame opposite the nose. The truck may then be set to roll on the pair of wheels located on the main frame alone or in combination with the auxiliary wheels as desired to minimize the amount of work to be expended by the handler.
Generally, the provision of the auxiliary wheels allows the hand truck to be supported on all four wheels with the main frame tilted at an acute angle with the ground or support surface. Objects can be loaded on the hand truck one on top of the other upwardly from the nose, with the objects reclining on the tilted main frame. The loaded hand truck can then be pulled or pushed using all four wheels, or the auxiliary wheels can be disengaged thereby allowing the hand truck to be moved on the two main wheels in a conventional manner.
Prior to the present disclosure, there has been no suggestion of moving the main frame of the hand truck to a horizontal or near horizontal position and of providing means for supporting the main frame in such a position elevated from the floor or support on which the wheels of the hand truck rest. In accordance with the present invention, it has been found highly desirable to provide means for positioning and supporting the main frame in a horizontal or near horizontal position elevated from the ground or floor upon which the wheels of the hand truck rest. Objects can then be moved from a rack, a truck bed or other storage area to the elevated main frame of the hand truck without undue up and down movement of the handler.
With all prior art hand trucks, the operator must bend over many times to load objects such as cases of cans or other items onto a hand truck, and then bend over again several times when unloading the cases. Heavy objects such as kegs of beer which can weigh up to 180 or more pounds are oftedn rolled off a truck, rack or conveyor system and bounced on the ground or floor. The operator must then turn the kegs upright and place one on top of the other on the hand truck. Such bending and lifting, especially when done successively hundreds of times each working day, can have serious effect on the operators health. Muscle strain, back injuries, etc. are very common for operators of this type. Such injuries may be minimized or eliminated by a hand truck in which the main frame can be positioned in a horizontal or near horizontal orientation at an optimum height above the ground or floor so as to alleviate any need for an operator to bend over to load or unload objects therefrom. When placed at an optimum height, very heavy objects such as kegs of beer can be rolled directly from the truck, storage racks, conveyors, etc. on to the hand truck without any lifting by the operator.
Further, in all prior art hand trucks utilizing auxiliary wheels, the mechanism for swinging the auxiliary wheels into and out of their operative position consists of an actuator that extends from one of the longitudinal sides of the hand truck. Such an actuator cannot be engaged by an operator who is standing at the backside of the hand truck in an operative position with his hands on the handle of the hand truck. It has been found that it is highly advantageous to provide an actuator mechanism that can be operated by the toe of the operator as the operator stands in operative position behind the hand truck with his hands on the handle of the hand truck.